Automobile engine starting device



Dec. 31, 1940. c] w. SPENCER 2,227,284

AUTOMOBILE ENGINE STARTING DEVICE Filed Aug. 12, 1959 2 Sheets-Sheet 1 41 11 10 2.] {Erwwhr Dec. 31, 1940. w, SPENCER 2,227,284

AUTOMOBILE ENGINE STARTING DEVICE Filed Aug. 12, 19:59

2 Sheets-Sheet 2 I 17 P'W 16 I w Patented Dec. 31, 1940 UNITED STATES PATENT, OFFICE AUTOMOBILE ENGINE STARTING DEVICE Carlton W. Spencer, Newton, Mass. Application August 12, 1939, Serial No. 289,821

1 Claim. (01. 74- 1) My present invention is a novel and improved device to be actuated by an electric motor for starting automobile engines or the like.

My present starting device or unit is of the general type of engine starting apparatus illustrated, for example, in U. S. Letters Patent Nos. 1,901,996 and 1,901,997, both dated March 21, 1933, although the invention is equally applicable to electrically actuated engine starting devices of other kinds.

An important object of my present invention is to so design and devise a starting unit that the same may be particularly adapted for application to automobile engines where compactness is important and where the engine design makes it difiicult for a starting unit to be incorporated therewith. Thus my present invention is primarily designed for an automobile engine wherein the standard type of engine starting device is diflicult to apply, as, for example, in the 1937 Chevrolet model of automobile engine.

It is, therefore, a special object of my present invention to so design my improved engine starter as to adapt the construction to assemble with and operate upon an engine of the Chevrolet type of construction.

A further important object of the present invention is to provide an extremely strong, simple and economical structure eliminating all danger of binding, jamming, or the like, and which will also enable the parts to be made with a minimum of expense and machine work.

A still further object of the invention is to provide an improved and novel type of pinion structure, which pinion is adapted to engage and rotate the usual ring gear of the fly wheel of the engine to be started. My present improvement includes means to adapt the pinion to engage the ring gear in an extremely confined space and with the armature shaft of the starter positioned in close proximity to the outer path of movement of the ring gear. This is a particularly important feature where compactness is necessary, and furthermore I have so arranged and constructed the pinion and cooperating parts of my present improved starter drive as to enable the pinion driving element to be closely adjacent the teeth of the pinion even where there is insufficient space to design a pinion with the driving element therefor directly underneath the driving teeth.

A further important feature consists in the construction and arrangement of parts permitting assemblies of the various elements constituting the starting and driving constructions, the improved arrangement of devices of this type for affording a bearing for the outer end of the armature shaft of the electric motor, and also the means and arrangement of providing bearing members, stops and collars to limit the longitudinal movement of the sliding parts of the driving mechanism, together with other features, advantages and improvements which will be more fully hereinafter pointed out and claimed.

Referring to the drawings illustrating a preferred embodiment of my invention,

Fig. 1 is a side elevation of a complete starter unit;

Fig. 2 is an enlarged longitudinal cross-sectional view of the enclosing casing but with the starting elements in full view and in non-driving position; I

Fig. 3 is a longitudinal cross-sectional view of the driving elements also shown in non-starting position; a

Fig. 4 is a corresponding longitudinal crosssectional view with the starting elements shown in starting position, and with the pinion engaging the ring gear of the engine to be started;

Fig. 5 is an enlarged end view of the line 5-5 of Fig. 2, showing the pinion looking to the left of Fig. 2;

Fig. 6 is a view in perspective of a part of my novel device to facilitate the assembling of the parts within the space afforded by the casing;

Fig. '7 is an enlarged cross-sectional view on the line I-I of Fig. 3;

Fig. 8 is a cross-sectional view in enlarged scale on the line 88 of Fig. 3; a

Fig. 9 is a cross-sectional view on the line 9-9 of Fig, 3.

Referring to the drawings showing in illustrative form a starter drive embodying my invention, I indicates the armature shaft on an electric motor secured to an extension shaft 2 by a coupling 3, said shaft 2 having a series of keyways 4 cut longitudinally therein, three such keyways 4 being shown and preferably employed to insure smooth sliding of the control nut 5, which is mounted on the shaft 2 and adapted to move longitudinally thereon, being provided with internal splines 6 adapted to fit said keyways, as best shown in Fig. 9. The control nut 5 is formed with screw threads on the outside as indicated at ID, which threads III engage corresponding internal threads I I in a sleeve I2, said sleeve having formed on the end opposite the motor, viz., at the right, viewing Figs. 1, 2, 3 and 4, a cone surface I4 which cone is adapted to engage and cooperate with a corresponding internal cone face I5 on the hub I6, which hub carries pinion teeth I! adapted to engage the corresponding teeth I8 in a ring gear on the engine to be started. The hub I6 is formed with the portion under the teeth I! adapted to bear upon and rotate freely on the outer circumference of the shaft 2. The pinion member at the end opposite to the cone face I5 has a circular recess l9 adapted to receive one end of a coiled flat spring 20 bearing between the wall of the recess I9 and the flange 2| of a collar 25, which collar is adapted to fit over the extending outer end of the shaft 2, said collar 25 being provided with three dentil clutch members 24 adapted to fit within the keyways 4.

The shaft 2 has a reduced portion as shown at 25 shouldered substantially the depth of the keyways 4 so that the collar 25 will present a smooth surface substantially of equal diameter to that of the normal part of the shaft 2 from the shoulder 26 outwardly or to the right viewing Figs. 1, 2, 3, and 4. Whereupon the pinion may slide over the outer surface of the collar 25 during the operation of the device and the compression of the spring 20. A circular groove 21 is provided in the shaft 2 at a proper space as shown in Figs. 3 and 4, and is fitted with a circular spring stop 28, which is adapted to engage an annular undercut groove 29 in the outer part of the collar 2| to constitute a stop for said collar as best shown in Fig. 3. The extreme outer end of the shaft 2 as indicated at 30 constitutes a bearing to rest in a bushing 3I secured by the bracket members 33 formed as a part of the casing 34 enclosing the starting elements, and such casing is attached to the motor enclosing casing 35. Formed integrally on the casing 34 is a rim 36 having recesses therethrough as indicated at 31 to permit attachment by bolts or otherwise to the engine structure.

I apply to the part of the shaft 2 adjacent the motor a coiled spring 40 bearing between the collar 3 and the face of the control nut 5, as best shown in Figs. 3 and 4. This spring 40 is a relatively strong and heavy coiled spring with an expansible tension, and normally tends to force the control nut to the right of the sleeve I2. Fitted in the endmost part of the threads I l in the sleeve I2 as indicated at M is a stop ring which will limit the movement of the control nut I2 relatively with the internal threads I I on the sleeve I2 when the shaft 2 is rotated, as will be explained.

The operation of the starter will now be described. Upon energizing the electric motor within the casing 35 by turning on the switch therefor from the armature shaft I is rotated together with the shaft 2, the starter parts'then being in the position shown in Figs. 1, 2 and 3, and hence out of mesh with the teeth on the ring gear I8. Owing to the inertia of the sleeve I0, hub I6 and pinion, together with the tension of the light coiled spring 20, these parts will cause the control nut 5, which 60 is rotated with the shaft 2 because of the splines 1 6 in the grooves 4 in said shaft, tomove the sleeve I2 and pinion to the right viewing the figures of the drawings and with the pinion teeth I! into mesh with the teeth on the ring gear I8. Contin- 65 ued rotation of the shaft 2 turns the nut 5 in the internal teeth of the sleeve l2 and builds up a torque or pressure therein through the tension of the heavy spring 40, as said spring is compressed by the nut 5 travelling to the left of the figures 70 until the same reaches the position illustrated in Fig. 4, when said nut engages the stop ring 4| and hence further rotative movement between the nut 5 and the sleeve I2 is ended. Therefore the sleeve will be locked into rotation with the shaft 2 and through the cone clutch between the surface I4 and I5 on said sleeve and the hub It will, of course, turn the pinion teeth I! and hence the ring gear I8, thus turning over theengine until the engine cylinders are fixed and thereupon a reverse rotation is effected, as the ring gear l8 will travel at a higher speed than that afforded by the starter drive. Because of the slippage afforded by the clutch between the sleeve I2 and the pinion, all danger of damage or injury to the mechanism is eliminated.

An important feature consists in the assembling of the parts constituting the drive, and particularly in the arrangement, construction and ease of assembly of the collar 25 with the flange 2|, which flange and collar constitute a forward stop and limit against which the pinion abuts. It will be noted that I desire to obtain the advantage incident to having the outer end 30 of the shaft 2 in abearing which is closely adjacent the ring gear so that the shaft gear will not spring or be distorted during the meshing of the pinion teeth I! with those of the ring gear I8. For this purpose I fit the collar 25 over the end of the shaft 2, and the same is coupled to said shaft by the teeth'24 meshing with the grooves 4, said collar being for the reduced part of the shaft 2, and with the collar 25 of a thickness equal to the reduced portion so that the surface of the collar 25 will constitute a sliding bearing for the pinion when the latter is forced into driving connection with the ring gear and hence operate the forward limit of movement in contact with flange 25, and as shown in Fig. 4. This arrangement permits me to assemble these parts and then to fit the shaft 2 into its bushing 3| in the bearing 32 on the bracket, and then to couple the shaft 2 with the armature shaft I. A flange 38 on the bushing 3| prevents the same from being displaced during this assembling of the shaft 2 thereon. The stop 28 is sprung into the groove 21 and then the collar 25 is locked firmly into position, as will be readily appreciated.

It will be noted that my improved construction is extremely simple, rugged, efilcient, and will insure long and continuous usefulness.

I claim:

An engine starting device of the kind described,

comprising a driving element in said starter and a driven element on said engine, a shaft adapted to be rotated by the starter driving element, said shaft including a portion formed in reduced diameter at the end opposite the driving element, a flanged collar adapted to fit over said reduced portion and movable longitudinally from said reduced portion, with means interlocking with the shaft to rotate therewith, the outer diameter of the body portion of said flanged collar being in alignment with the outward diameter of the main part of said shaft, a pinion adapted to transmit rotative power from the shaft to the driven element of the engine and arranged to slide longitudinally over said flanged collar during the engine starting opera,- tion, clutching means to unite the pinion for imparting rotative action thereto from said shaft, and means to release said clutching action when the engine is rotating at greater speed than that of the starter drive shaft.

CARLTON W. SPENCER. 

